1. Field of Invention
The present invention relates generally to the field of communication and data networks. More particularly, in one exemplary aspect, the present invention is directed to methods and apparatus for bridging between circuit-switched (e.g., PSTN or POTS) and packet-switched (e.g., VoIP or digital wireless) communications environments.
2. Description of Related Technology
Voice over Internet Protocol (VoIP) is a general term for a family of transmission technologies adapted for delivery of voice communications over the Internet or other packet-switched networks. VoIP systems typically interface with a traditional public switched telephone network (PSTN) or plain-old telephone system (POTS) to allow for effectively transparent phone communications with existing non-packet switched infrastructure. VoIP can be beneficial for, inter alia, reducing communication and infrastructure costs by routing phone calls over existing data networks, and avoiding duplicate network systems.
Wireless technology enables a plurality of user devices (e.g., mobile telephones, hand-held devices such as PDAs, or laptop computers) to communicate without wires, thereby enabling a wide variety of desirable applications leveraging improved mobility and convenience for the user. One such wireless technology is known as wireless Local Area Networking (LAN) or WLAN, such as for example one compliant with IEEE Std. 802.11 (“Wi-Fi™”). Wi-Fi is one exemplary wireless technology providing network access via spread-spectrum or Orthogonal Frequency Division Multiplexing (OFDM) modulation techniques. WLAN installations and “hot spots” are highly popular for a wide-ranging audience including everyone from home users and small businesses operators to large corporations and even city-wide publicly offered access. The ease of WLAN installation/operation, along with a large amount of market penetration and a plethora of WLAN capable devices (e.g. laptops, smartphones, etc.) help ensure WLAN's future growth and continued popularity.
Wireless phones that make use of both VoIP and WLAN protocols are now prevalent in the marketplace. For example, Netgear™ manufactures a Wi-Fi phone for use with the Skype™ VoIP service, while UTStarcom™ manufactures a Wi-Fi phone for use with the Vonage™ service. In order to use either of these phones, one must have an account with that provider, generally analogous to a service plan from a cell phone service provider for use a particular cellular phone. The phone is then configured the phone to work within the network.
Cellular telephone technology, such as the Universal Mobile Telecommunications System (UMTS) is an exemplary implementation of a cellular telephone technology. The UMTS standard is specified by a collaborative body referred to as the 3rd Generation Partnership Project (3GPP). Other types of cellular technology include without limitation analog cellular (e.g., AMPS), so-called “2G” systems (e.g., GSM and IS-95A CDMA), “2.5G” systems (such as EDGE), and LTE (long term evolution) systems.
VoIP, PSTN/POTS, and cellular telephone networks are currently capable of some degree of interoperation (i.e., a VoIP user could make and receive phone calls with other users of a PSTN or a cellular telephone network via, e.g., a gateway or other bridging device). However, despite this interoperability, such traditional solutions fail to provide adequate support for integrating these various services (i.e., VoIP, PSTN/POTS, cellular, etc.) for a single user. For example, a given user may have a “landline” or PSTN/POTS telephone service at their residence, and may also have a cellular telephone subscription (e.g., 3G UMTS), but there is effectively no cooperation or crossover between the two networks. One can call their cellular phone from their PSTN/POTS line and vice versa (interoperability), but a call received on the PSTN/POTS line is not forwarded or connected to the cellular phone (except via “call forwarding” functionality if present, which adds cost along with any charges incurred through use of the cellular network).
Moreover, traditional call forwarding technologies require changes to their configuration as the user's situation changes; for example, a user wanting a PSTN/POTS call forwarded to their cellular phone under a first circumstance (e.g., they are at the pool of their apartment building) then must “unforward” the call when they return to their apartment in order to utilize the PSTN/POTS infrastructure (e.g., their cordless 900 MHz or 5.8 GHz phone), or their PC-based phone.
Hence, what is needed are improved apparatus and methods that allow for interoperability as well as unification or crossover between different call environments and network topologies. Such an improved solution should operate seamlessly and without adversely impacting user experience, so that voice or data available in one domain (e.g. analog PSTN/POTS) can be seamlessly forwarded onto another domain (e.g., digital WLAN or PAN). For example, a user could receive a telephone call via a PSTN/POTS line and forward that telephone call (or information related to that call, such as a caller's message) over another network such as a “local” wireless network (e.g., a WLAN) to the user, where the user can answer the call (or access the forwarded information).
Ideally, such improved apparatus and methods would also be bidirectional in operation so that a user could access the bridge device via the local network, and forward on voice and/or data via the bridge device to a PSTN/POTS or other call environment. Significant flexibility would also be offered to the user in terms of location, and power consumption aspects of the mobile device (e.g., cellular phone or smartphone) acting as a cordless “proxy”.